1. Field of the Invention
The present invention relates to an apparatus and method for stacking multiple products that do not have a uniform size. More specifically, the apparatus and method stacks products of varying horizontal size utilizing a design that allows for packaging objects of varying size into packages of a single standard size. The apparatus and method is fast, efficient and reliable.
2. Prior Art
Pastries are a multi million dollar a year business in the United States. The manufacture and sale of donuts is especially lucrative. Many companies package their donuts for later sale in grocery stores or super markets. Unfortunately, packaging donuts has proven very problematic. Because donuts and other pastries rise during baking, end products are not uniformly shaped. Automated packaging machinery typically requires products having precise, uniform shapes. This had caused a development of suitable donut packaging machinery to be very problematic. Because they are of varying size and shape, they generally cause packaging machines to become clogged and the donuts to become smashed or malformed.
Currently systems that automatically handle products of a fairly uniform shape and size exist. In the food industry, a good example of this type of product is a sandwich cookie. There is a large amount of prior art that deals with the handling of these uniform types of products. Despite numerous attempts, efforts to use these systems with products that have a large variation in size have been a total failure. Because of these failures, these variable size products are loaded into the horizontal wrapper, or other secondary system, by hand. This is very costly and labor intensive.
There have been several attempts in the past to develop machines capable of stacking and packaging multiple donuts.
U.S. Pat. No. 3,745,740 to Williams discloses a packaging method and apparatus that stacks donuts and other objects having similar shapes. The patent discloses a method of stacking donuts by dropping them into a cylinder. A moving rod then lowers a stack of donuts into a package. The objects are stacked vertically, not horizontally. This patent does not disclose the use of a rotating drum having successive wells in it.
U.S. Pat. No. 4,162,870 to Storm discloses a device to horizontally stack donuts and similar products. A lever lifts objects onto their edge and places them in a horizontal stack held in place by lever arm and a piston. It then drops the objects into a package. It does not disclose the use of a rotating drum to package donuts.
U.S. Pat. No. 5,480,278 to Morgan discloses a apparatus and method for stacking frozen patties and other objects having similar shape. A conveyor belt moves the patties onto a piston. After a pre-determined number of patties are rested upon the piston, the piston moves upward to a horizontal platform where they are pushed off the piston. This process is then repeated. The frozen patties are stacked vertically, not horizontally. Furthermore, the stacking action is not continuous. When the piston moves up to the horizontal platform. The stacking action must stop, requiring a discontinuous, slower process. This patent does not disclose the use of a rotating drum to stack objects having variable sizes.
U.S. Pat. No. 5,809,745 to Reinert discloses another method for vertically stacking frozen patties and similar objects. This invention uses a rotating cam to lift objects to the bottom of a stack. The objects are vertically stacked and are not on edge. Stacking from the bottom up, as shown in this patent is not suitable for soft objects such as donuts and pastries. Such stacking action would result in the crushing of the product. Furthermore, the patent does not disclose a rotating drum for packaging donuts.
U.S. Pat. No. 5,765,337 to Lodewegen et al., discloses another method for vertically stacking cylindrical objects. It provides for vertically not horizontally, stacked items. It also does not disclose the use of a rotating drum to stack variable size objects.
U.S. Pat. No. 6,182,814 to Koehler discloses a method of separating a continuous row of on-edge objects into smaller groups. It uses a vacuum and slugs to separate objects that are already on edge. While the objects are horizontally stacked, it does not disclose the use of a rotating drum to accomplish this.
U.S. Pat. No. 6,052,969 to Hart et al., discloses a method of stacking cylindrically shaped products. A conveyor belt drops the objects into a stacker thereby placing them on edge. Once the stacking device is full, it transfers the stack to a package. The invention disclosed in this patent is most suitable for hard objects such as frozen patties. Soft objects, such as donuts and pastries, would not stack properly in this device and would probably be significantly damaged. This device does not disclose the use of a rotating drum to package cylindrical objects.
U.S. Pat. No. 3,849,969 to Paules discloses a device that individually wraps frozen patties prior to their being stacked on pistons. The patties are stacked vertically, not horizontally. In addition, this device is only suitable for relatively sturdy objects such as frozen patties. Softer objects, such as donuts would be damaged by such a machine. It also does not disclose the use of a rotating drum to package cylindrical objects.
U.S. Pat. No. 3,959,951 to Paules discloses an apparatus very similar to the one described in the preceding paragraph. It is suitable only for vertically stacking frozen patties. It would be damaging to softer products. It also does not disclose the use of a rotating drum to package products on edge.
U.S. Pat. No. 5,235,796 to Campbell, III et al., discloses a method for stacking and packaging small planar objects such as cookies and crackers. A conveyor belt dumps the objects onto a machine designed to vertically stack them. Once the stacking unit is full, it pivots downward and releases the objects into a package. Arms on the stacking unit rotate outward to allow the stacked objects to be released into the package. The pivoting motion of the stacking unit requires that the packaging be performed in a discontinuous fashion. Stacking must stop when the stacking unit places objects into a package. This patent also does not provide a method of stacking objects of variable size into a standard size package. This patent also does not disclose the use of a rotating drum to provide for continuous packaging.